An arrangement for reading the indentations in a key is known heretofore, one example being that shown in my previous U.S. Pat. No. 3,226,811 in which the indentations along the edge of a pre-formed key are read and the information there obtained is used to manufacture a lock with which that key would be used. However, while that key reading structure would be operable for its intended purpose, it has the disadvantage of being relatively slow and of lacking the sensitivity to read and discern different depths of indentations wherein the differences in depth between successive depth stages is relatively small as is the case for example in the type of key as shown in U.S. Pat. No. 3,393,542 which has "dimple" indentations formed into the flat sides of the key blade. In this case the tumblers move transverse to the plane of the key into said dimples to effect an opening position of the lock.
Hence, there exists a need for a new and improved key reading method and apparatus which will overcome the disadvantages of the prior art.